Elevating generators and pumps is a good idea, but enclosing elevated foundations that might be hit by waves or wave-borne debris may be a mistake, they say.

Builders attending the National Hurricane Conference in New Orleans this week also say elevating homes on piers reduces the danger from flooding, but more study is needed on ways to keep slab foundations from lifting out of the ground.

Erin Ashley of URS Corp., a contractor that did damage estimates after Hurricane Isaac struck Louisiana last August, says inspectors saw numerous houses that looked fine but had cracked slabs because they were raised without enough permanent reinforcement.